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Biomedical subjects

Stephen R Archacki

Publications and source records attributed to Stephen R Archacki.

3 recordsLinked to original sources

Microarray analysis of cardiovascular diseases.

Microarray analysis is a powerful technique for high-throughput, global transcriptonomic profiling of gene expression. It holds great promise for analyzing the genetic and molecular bases of cardiovascular diseases and various other complex diseases and permits the analysis of thousands of genes simultaneously, both in diseased and nondiseased tissues and/or cell lines. Microarrays or microchips are made by depositing spots of DNA or oligonucleotides representing thousands of genes on a solid support such as a coated glass surface, and can allow the comparison of gene expression patterns in any two samples. Total RNA is isolated from the tissue or cells of interest, converted to cDNA and then cRNA labeled with biotin, and hybridized to the chips. Hybridization signals are then quantified and compared among different samples. We used oligonucleotide microarrays to obtain an unbiased assessment of expression levels of thousands of genes simultaneously in normal and diseased coronary arteries. Fifty-six genes showed differential expression in atherosclerotic coronary artery tissues, and 49 of them represent new linked genes for coronary artery disease. These studies can generate novel hypotheses relating to the pathologies of disease and further studies with animal models, molecular biology, cell biology, and biochemistry will validate these hypotheses and provide novel insights into the pathogenesis of disease.

Biotin↗

Identification of new genes differentially expressed in coronary artery disease by expression profiling.

Genetic factors increase the risk to coronary artery disease (CAD). To date, a limited number of genes that potentially contribute to development of CAD have been identified. In this study, we have performed large-scale gene expression analysis of approximately 12,000 human genes in nine severely atherosclerotic and six nonatherosclerotic human coronary arteries using oligonucleotide microarrays. Fifty-six genes showed differential expression in atherosclerotic coronary artery tissues; expression of 55 genes was increased in atherosclerotic coronary arteries, whereas only one gene, GST, encoding a reducing agent, showed downregulated expression. The expression data of selected genes were validated by quantitative RT-PCR analysis as well as immunostaining. The associations of 49 genes with CAD appear to be novel, and they include genes encoding ICAM-2, PIM-2, ECGF1, fusin, B cell activator (BL34, GOS8), Rho GTPase activating protein-4, retinoic acid receptor responder, beta2-arrestin, membrane aminopeptidase, cathepsins K and H, MIR-7, TNF-alpha-induced protein 2 (B94), and flavocytochrome 558. In conclusion, we have identified 56 genes whose expression is associated with CAD, and 49 of them may represent new genes linked to CAD.

Apoptosis↗

Proteomic approach to coronary atherosclerosis shows ferritin light chain as a significant marker: evidence consistent with iron hypothesis in atherosclerosis.

Coronary artery disease (CAD) is the leading cause of mortality and morbidity in developed nations. We hypothesized that CAD is associated with distinct patterns of protein expression in the coronary arteries, and we have begun to employ proteomics to identify differentially expressed proteins in diseased coronary arteries. Two-dimensional (2-D) gel electrophoresis of proteins and subsequent mass spectrometric analysis identified the ferritin light chain as differentially expressed between 10 coronary arteries from patients with CAD and 7 coronary arteries from normal individuals. Western blot analysis indicated significantly increased expression of the ferritin light chain in the diseased coronary arteries (1.41 vs. 0.75; P = 0.01). Quantitative real-time PCR analysis showed that expression of ferritin light chain mRNA was decreased in diseased tissues (0.70 vs. 1.17; P = 0.013), suggesting that increased expression of ferritin light chain in CAD coronary arteries may be related to increased protein stability or upregulation of expression at the posttranscriptional level in the diseased tissues. Ferritin light chain protein mediates storage of iron in cells. We speculate that increased expression of the ferritin light chain may contribute to pathogenesis of CAD by modulating oxidation of lipids within the vessel wall through the generation of reactive oxygen species. Our results provide in situ proteomic evidence consistent with the "iron hypothesis," which proposes an association between excessive iron storage and a high risk of CAD. However, it is also possible that the increased ferritin expression in diseased coronary arteries is a consequence, rather than a cause, of CAD.

Adult↗